A polyamide is one of the polymers which are frequently used as engineering plastics for a very wide range of applications.
A polyamide molding composition is of significant commercial interest and may be used to produce housings or housing parts of electrical and electronic apparatuses, for example housings for mobile phone, generally by injection molding.
For particular applications, such as housings or housing parts of electrical and electronic apparatuses, required is a polyamide molding composition which is capable of exhibiting properties such as light weight, high stiffness, low warpage, excellent surface quality, and minimum distortion during injection molding.
In general, polyamides have hygroscopic properties and will thus become degraded by excessive moisture during injection molding process. Further, it is well known in the field that a novolac resin can be used to reduce moisture content in a polyamide composition and thus increase dimensional stability of the articles produced using the polyamide composition. For instance, U.S. patent application publication No. 2010/0227962 A1 discloses the use of a novolac resin for increasing the rheological behavior of a polyamide composition, such polyamide composition comprising a novolac resin, and also its use for manufacturing molded parts, especially by injection molding. In this regard, however, a novolac resin has a drawback of decreasing mechanical properties of polyamide composition, e.g., tensile/flexural modulus, tensile/flexural stress, impact strength, etc. Therefore, a polyamide composition comprising a novolac resin, which can reduce moisture content while maintaining advantageous mechanical properties at a time, is a current shortfall in this technology field.